Drifting-valve for locomotives.



P. J. COLE. DRIFTING VALVE FOR LOCOMOTIVES.

APPLIOATXON FILED NOV.19,1912 1,089,904. Patented Mar. 10, 1914.

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"FIG- 1:-

INVENTOR P. J. COLE. DRIFTING VALVE ron LOCOMOTIVES.

APPLICATION TILED NOV. 19, 1912.

Patented Mar. 10, 1914 same in both cases.

FFICE FRANCIS J. COLE, 01F SCHENECTADY, NEW YORK,

DRIFTING-VALVE FOR LOCOMOTIVES.

Specification of Letters Patent.

Patented Mar. 10, 19. 4.

Application filed November 19, 1912.. Serial No. 732,206.

To all whom it may concern:

Be it known that I, FRANCIS J. Cons, of Schenectady, in the county of Schenectady and State of New York, have invented a certain new and useful Improvement in Dr fting-Valves for Locomotives, of which improvement the following is a specification.

The object of my invention is to provide simple and inexpensive means for automatically effecting the admission of a limited quantity of steam, directly from the boiler to the valve chests and cylinders of a locomotive engine, during the periods in which the locomotive is drifting or running with its throttle closed, in order to prevent the formation of a vacuum in the cylinders andprevent overheating and undue wear of the parts which are in frictional contact.

The improvement claimed is hereinafter fully set forth.

In the accompanying drawings: Figure 1 is a side view, in elevation, of so much of the forward portion of a locomotive engine as illustrates the application of my invention thereto; Fig. 2, a vertical central section, on an enlarged scale, through the drifting valve mechanism; and, Fig. 3, a plan or top view of the same.

It is well known to those familiar with the operation of locomotives that the wear on packing rings and cylinder and valve chest rubbing surfaces is materially greater when the steam is shut off by the closure of the throttle valve, and the locomotive is drifting, than when steam is passing throu h the valve chests and cylinders under or inary running conditions. This is due to the fact that, in the latter case, the exhaust steam carries off the excess heat produced by the friction of the wearing parts and keeps their temperature within reasonable limits. The friction of the valves and istons, when the steam is shut off and the ocomotive is drifting down long grades, produces considerable heat, whereby the temperature of the wearing parts is abnormally raised, resulting in undue wear, notwithstanding the fact that the quantity of oil used may be the The condition above stated is especially true in the case of locomotives which are equipped with superheaters, the parts subject to wear being much hotter than in locomotives usin saturated steam, and, conse uently, a sma erincrease in temperature 110 to friction 1s more quickly effective in the wear of cylinders, packing rings, bushings, etc., than when saturated steam is used.

A method which has been practised, in the endeavor to obviate or reduce the objectionable results referred to. is to slightly openor crack the throttle valve, when dr fting down long grades, in order to admit a small quantity of steam to the valve chests and cylinders. This practice is, however, for obvious reasons, undesirable, and particularly so in the case of locomotives equipped with superheaters, by reason of the high heat of the superheated steam admitted to the cylinders.

When a locomotive is drifting, there then being no steam in the cylinders, the movements of the pistons therein, produce a vacuum in each of the valve chests, and for this reason, air admission or so called vacuum valves are usually fitted on the valve chests. The function of these valves is to admit a small quantity of air to the cylinders, in order to reduce the vacuum therein and also to prevent hot gases and cinders from being drawn from the smoke box into the exhaust pipes. The area of these vacuum valves is necessarily so small that it is impossible to supply air in sufiicient quantities to the valve chests to prevent the production of a partial vacuum, and, as another means of prevention, by-pass valves are often applied.

My invention is designed to utilize the tendency to the formation of a partial vacuum in the cylinders and valve chests, to effeet the automatic supply of steam to the cylinders when the locomotive is drifting.

Referring to the drawings, in the practice of my invention, I locate in any convenient position adjacent to each of the valve chests, 1, of the locomotive, a diaphragm chamber, 2, that is to say, a separate diaphragm chamber is provided for each valve chest, said chamber being connected therewith by a pipe, 3. A flexible diaphragm, 4, extends across the bottom of each of the chambers, 2, to which it is secured at its periphery, a hermetically sealed joint being made. A

cover plate, 5, havin one or more air openings, 5, extending t rough it, is secured to the chamber, 2, below the diaphragm, 4, the object of said cover plate being to prevent distortion of the diaphragm in the event of the accumulation of pressure in the chamber when the locomotive is working under Q nosaeoe I steam. A steam supply chamber, 6, and a steam deliver chamber, 7, are fixed to the top of the diaphragm chamber, 2, being preferably, as shown, formed integral therewith, and being separated by a partition, 8, in which there is formed an opening controlled by a steam supply valve, 9, of the puppet type, which seats downwardly, or in the direction of the steam delivery chamber, 7. The steam supply chamber, 6, communicates, by a pipe, 10 with the steam space of the boiler, 11, and a pipe, 12, leads from the steam delivery chamber, 7, to the pipe, 3, leading to the valve chest.

A piston, 13, of materially greater diameter than the valve, 9, is fitted in a chamber, 13*, below, and substantially in line axially with, the valve, 9, the top of said piston being normally in contact with, or slightly below, the downwardly projecting stem, 9, of said valve, so as to be adapted to unseat it by its upward movement. A passage, 14, leads from the steam supply chamber, 6, to the piston chamber, 13, said passage being controlled by a small pilot valve, 15, the stem, 15*, of which, extends downwardly to or near the bottom of a central socket, 16, formed in a bearing plate, 16, which rests on the top of the diaphragm, 4:-

In the operation of the appliance above described, when the locomotive is drifting, and a partial vacuum is formed in the valve chests, a corresponding reduction of pressure results in each of the diaphragm chambers above the diaphragm, 4, thereof, which is thereupon forced upwardly by the higher atmospheric pressure below it of the air which enters through the opening, 5*. The upward movement of the diaphragm unseats the pilot valve, 15, thereby admitting steam from the pipe, 10, and chamber, 6, tn

the piston chamber, 13*", below the piston, 13.

Said piston is thereby moved upwardly, unseating the supply valve, 9, and admitting steam from the boiler, through the pipe, 10, chambers, 6, and 7, and pipes, 12, and 3, to thevalve chest. When the throttle is opened for the purpose of working the locomotive under steam, the diaphragm is depressed by the then higher pressure above it, and the valves, 15, and 9, are seated by the. same higher pressure, the parts being thereby returned to the normal positions shown in Fig. .2.

I claim as my invention and desire to s'e cure by Letters Patent 1. In a drifting valve appliance for 10- comotives, the combination of a diaphragm chamber, a flexible diaphragm closmg one end of said chamber and subject to atmospheric pressure on its outer side, a ipe for connecting said chamber with a istribu-- tion valve chest, a steam supply chamber and a steam delivery chamber, a steam supply valve controllin communication between said supply and delivery chambers, a pipe for connecti the steam supply chamber with a locomotive boiler, a plpe for connecting the steam delivery chamber with a distribution valve chest, a piston, of larger diameter than the steam supply valve and adapted to unseat said valve, a pilot valve controlling the supply of steam to said '-piston, and a stem interposed between said pilot valve and the flexible diaphragm, whereby said valve is automatically unseated by the movement of the diaphragm under atmospheric pressure when the locomotive is drifting with throttle closed.

2. In a drifting valve appliance for locomotives, the combination of a diaphra chamber, a flexible diaphragm extending across one end of said chamber, a perforated cover plate secured to the chamber on the outer side of the diaphragm, a.pipe extend-- ing, from said chamber to a distribution valve chest, a steam supply chamber and a steam delivery chamber integral with and located on one side of the center line of the diaphragm chamber, a pipe for connecting the steam supply chamber with a locomotive boiler, a steam supply valve controllingcommunication between the steam supply and delivery chambers, a piston of larger diameter than the supply valve, fitted in a chamber in the steam delivery chamber below the steam supply valve and adapted to unseat said valve, a pilot valve controlling the supply of steam to said stem interposed between said pllot valve and the flexible diaphragm, through which stem the pilot valve is automatical y unseated by the inward movement of the diaphragm under atmospheric pressure when the loco- 105 motive is drifting with throttle closed.

FRANCIS J, COLE. Witnesses: 1

S. W. TYLER, F. F. ScovILLn.

piston, and a 

